<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<style>
    div{
        width:400px;
        height:200px;
        border:30px solid olivedrab;
        outline:5px dashed red; /*轮廓*/
    }
</style>
<body>
    

    <div></div>
</body>
</html>